Fix fdo#80447: Help pages for MS BINOM functions

Covers BIMOM.DIST and BINOM.INV

Change-Id: If1f3ef61dfa5e23c6b88818439be2932eb98aabe
Reviewed-on: https://gerrit.libreoffice.org/10409
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>